Helical pile is an invention in pile foundation with a main objective of increasing pile capacity. According to Prasad, et.al (1996), definition of helical pile is a pile foundation that equipped with one or more helix that has a round shape, attached to the shaft with a certain distance between helixes. The aim of this study is to understand the effect of helixes number to the bearing capacity. In this study, empirical model is validated with the static loading test on three different type of helical pile: 1) single shaft, 2) helical pile with the same diameter of helixes and, 3) helical pile with different diameter of helixes on clay soil. The diameter of helixes are 15 cm, 20 cm, and 25 cm with distance between helixes 50 cm. The result shows the bearing capacity increase of single shaft to helical pile 252% - 369%. Moreover, the comparison of bearing capacity between helical pile with the same diameter of helixes and helical pile with different diameter of helixes is explained in this study.

Keywords : Helical Pile, Axial Compressive Capacity, Helical Diameter, Clay Soil, Static Loading Test.